<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta http-equiv="X-UA-Compatible" content="IE=edge" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <link rel="stylesheet" href="./css/30inputnumber.css" />
  <link rel="stylesheet" href="./css/30index.css" />
  <title>购物车</title>
</head>

<body>
  <div class="app-container" id="app">
    <!-- 顶部banner -->
    <div class="banner-box">
      <img src="images/fruit.jpg" alt="" />
    </div>
    <!-- 面包屑 -->
    <div class="breadcrumb">
      <span>🏠</span>
      /
      <span>购物车</span>
    </div>
    <!-- 购物车主体 -->
    <div v-if="fruitList.length > 0" class="main">
      <div class="table">
        <!-- 头部 -->
        <div class="thead">
          <div class="tr">
            <div class="th">选中</div>
            <div class="th th-pic">图片</div>
            <div class="th">单价</div>
            <div class="th num-th">个数</div>
            <div class="th">小计</div>
            <div class="th">操作</div>
          </div>
        </div>
        <!-- 身体 -->
        <div class="tbody">
          <div v-for="(item, index) in fruitList" class="tr" :class="{active: item.isChecked}">
            <div class="td">
              <input type="checkbox" v-model="item.isChecked" />
            </div>
            <div class="td">
              <img :src="item.icon" alt="" />
            </div>
            <div class="td">{{ item.price }}</div>
            <div class="td">
              <div class="my-input-number">
                <button :disabled="item.num <= 1" v-on:click="minusNum(item.id)" class="decrease">
                  -
                </button>
                <span class="my-input__inner">{{ item.num }}</span>
                <button @click="addNum(item.id)" class="increase">+</button>
              </div>
            </div>
            <div class="td">{{ item.price * item.num }}</div>
            <div class="td" @click="del(item.id)"><button>删除</button></div>
          </div>
        </div>
      </div>
      <!-- 底部 -->
      <div class="bottom">
        <!-- 全选 -->
        <label class="check-all">
          <input type="checkbox" v-model="isSelectAll" />
          全选
        </label>
        <div class="right-box">
          <!-- 所有商品总价 -->
          <span class="price-box">总价&nbsp;&nbsp;:&nbsp;&nbsp;¥&nbsp;<span class="price">{{ totalPrice }}</span></span>
          <!-- 结算按钮 -->
          <button class="pay">结算( {{ totalCount }} )</button>
        </div>
      </div>
    </div>
    <!-- 空车 -->
    <div v-else class="empty">🛒空空如也</div>
  </div>
  <script src="./vue.js"></script>
  <script>
    const defaultArr = [
      {
        id: 1,
        icon: "./images/火龙果.png",
        isChecked: true,
        num: 2,
        price: 6,
      },
      {
        id: 2,
        icon: "./images/荔枝.png",
        isChecked: false,
        num: 7,
        price: 20,
      },
      {
        id: 3,
        icon: "./images/榴莲.png",
        isChecked: false,
        num: 3,
        price: 40,
      },
      {
        id: 4,
        icon: "./images/鸭梨.png",
        isChecked: true,
        num: 10,
        price: 3,
      },
      {
        id: 5,
        icon: "./images/樱桃.png",
        isChecked: false,
        num: 20,
        price: 34,
      },
    ]
    const app = new Vue({
      el: "#app",
      data: {
        // 水果列表
        fruitList: JSON.parse(localStorage.getItem('list')) || defaultArr // 这里defaultArr只是测试使用,实际应该从服务器中获取
      },
      methods: {
        minusNum(id) {
          // 根据id找到数组中的对应项
          const fruit = this.fruitList.find((item) => item.id === id);
          // 操作num数量
          fruit.num--;
        },
        addNum(id) {
          // 根据id找到数组中的对应项
          const fruit = this.fruitList.find((item) => item.id === id);
          // 操作num数量
          fruit.num++;
        },
        del(id) {
          this.fruitList = this.fruitList.filter((item) => item.id !== id);
        },
      },
      computed: {
        // 默认计算属性,只能获取不能设置,要设置需要写完整写法
        // isSelectAll (){
        //     // 必须所有的小选框都选中,全选按钮才选中
        //     // every 必须所有item为true才为true
        //     return this.fruitList.every(item => item.isChecked === true)
        // },
        isSelectAll: {
          get() {
            // 用于设置全选按钮的状态
            return this.fruitList.every(item => item.isChecked === true)
          },
          set(value) {
            // 处理全选复选框, 当isSelectAll的值发生变化时,会执行此方法
            // 基于拿到的布尔值,要让所有的小选框 同步状态
            this.fruitList.forEach(item => item.isChecked = value)
          }
        },
        // 统计选中的总数
        totalCount() {
          return this.fruitList.reduce((sum, item) => {
            console.log(111111111111111111)
            if (item.isChecked) {
              // 选中 -> 需要累加
              return sum + item.num
            } else {
              // 没选中 -> 不需要累加
              return sum
            }
          }, 0)
        },
        totalPrice() {
          // sum => 阶段性的累加结果
          return this.fruitList.reduce((sum, item) => {
            if (item.isChecked) {
              // 选中 -> 需要累加
              return sum + item.num * item.price
            } else {
              return sum
            }
          }, 0)
        }
      },
      watch: {
        // 使用 watch 监视数据,并将数据保存在本地
        fruitList: {
          deep: true,
          handler(newValue) {
            // 需要将变化后的 newValue 存入本地 (转json)
            localStorage.setItem("list", JSON.stringify(newValue))
          }
        }
      }
    });
  </script>
</body>

</html>